Broadband gallium nitride (GaN) distributed amplifiers (DAs) covering multi-decades of bandwidth and providing high third-order intercept point linearity can enable advanced radio communication such as software-defined radios, linear fiber optic, instrumentation, and frequency-agile wireless applications. A high-linearity DA operating to millimeter-wave frequencies can be particularly enabling for 100+ gigabits per second (Gbps) coherent-linear fiber optics and instrumentation applications. However, up until now, efforts to increase linearity have been made at the expense of gain-bandwidth, which has limited high-linearity DAs to a microwave frequency range that is less than 20 GHz. Thus, a need remains for DAs that have increased linearity and gain-bandwidth.